wedding ring

Once upon a time, a nerd met a girl. Things happen as they do, and eventually [Ben] wanted to create the be-all, end-all engagement ring. (here’s a cache) It’s a simple titanium affair with 23 stones around the perimeter. What makes this ring so cool, though, is that it lights up whenever [Ben] and his girl are holding hands.

The metalworking portion of the build was about as easy as you would expect machining titanium to be. After the ring was cut off its bar stock, [Ben] brought it over to a mill where 23 holes for each of the stones were drilled. The stones were affixed to the ring with jewelers epoxy and the entire ring was buffed to an amazing shine.

The electronics are where this project really shines. Putting a battery of capacitor inside a ring is nigh impossible, so [Ben] decided to power the LEDs with an inductive charging circuit. A coil of wire wound around kapton tape serves as the inductor and a small SMD capacitor powers three very bright and very tiny LEDs.

The inductive charging unit itself is a masterpiece of hackery; [Ben] wanted the ring to light up whenever he and his ladyfriend were holding hands. To do this, [Ben]’s inductive charger is also a wearable device: a large coil of wire is the charger’s transformer and was would to fit around [Ben]’s wrist. The entire charging circuit can be easily hidden under a jacket sleeve, making for a nearly magical light-up ring.

An awesome piece of work, and one of the best jewelry builds we’ve seen in a long time. You can see the inductive coupling and shining LEDs in the video below.

To solder palladium to titanium [Jeremy] would need special equipment, so he found another way to mate the dissimilar metals. He milled a dovetail groove in the center of the titanium band. To do that, he had to make a special cutting tool that was just the right size. Once had milled the ring’s rough dimensions, he had to fabricate a custom mandrel to hold the ring for the rest of the job. The dovetail was then filled with a palladium strip using a combination of heat and hammering. The two ends are soldered together using palladium solder. The ring in the middle shows this solder joint. To the right is a ring after the inlay is milled flush but before the final polishing which will bring out the best qualities of both metals.